Among the interesting people encountered by my wife and me, during some recent vacation travel, were a small group of adolescent boys from a Navajo reservation. They were being led on a bicycle tour by a couple of white men, one of whom was apparently their teacher on the reservation.

The Navajo youngsters were bright and cheerful lads, so I was surprised when someone asked them in what state Pittsburgh was located and none of them knew. Then they were offered a clue that it was in the same state as Philadelphia but they didn't know where Philadelphia was either.

These Navajo boys seemed too bright not to have learned such things if they had been taught the basics. They also seemed too positive to be the kinds of kids who refused to learn.

The most likely explanation was that they were being taught other things, things considered "relevant" to their life and culture on the reservation.

These youngsters are not just members of the tribe on the reservation. They are also citizens of the United States of America, and have a right to be anywhere in this country, from Florida to Alaska.

Whether they want to stay on the reservation when they are grown or to take advantage of the many opportunities in the wider world beyond the reservation is a decision that should be theirs to make when they reach adulthood.

But those opportunities will be gone, for all practical purposes, if their education does not equip them with the knowledge that is needed to bring their natural abilities to the point where they are capable of doing all sorts of things in all sorts of places.

One of the men who was with these boys expressed great respect for the Navajo culture and there is no reason to doubt that he has good reasons for that conclusion.

But any culture -- whether in or out of the mainstream -- is not just a badge of identity or a museum piece to be admired by others.

A culture is a tool for serving the many practical purposes of life, from making a living to curing diseases. As a tool, it has to change with the ever changing tasks that confront every culture as time goes on.

Although we speak English today, we would have a hard time trying to understand things written in Old English from centuries ago. Languages, like every other aspect of culture, change over time.

Wind-driven sailing ships were a great advance over ships propelled by oars but the sailing ships were in turn superseded by steamships and today we have diesel-powered ships.

No culture can stand still.

Among the Navajo heroes of World War II were men who served in American armed forces in the Pacific and broadcast secret military messages in the Navajo language, which the Japanese were unable to translate.

This required the Navajo code-talkers to come up with new words for things like battleships and airplanes, which had never been part of traditional Navajo culture.

Some of these men were too old to be in the military, or too young, but they volunteered to serve anyway. This was an era when people from every background considered themselves Americans and wanted to help defend this country.

We can only hope that there are many more such people now, ready to serve both their country and their people, and that they will see to it that those promising young Navajo boys end up knowing all they need to know in order to be all that they can be.

Unfortunately, in this age of "multiculturalism," there are too many outsiders who want all sorts of cultures to be frozen where they are, preserved like museum exhibits.

Worse yet, too many multiculturalists want many groups to cling to their historic grievances, if not be defined by them.

But among the many ways that various groups around the world have advanced from poverty to prosperity, nursing historic grievances does not have a promising track record -- except for those who make a career out of keeping grievances alive.